Neurophysiological markers of identifying regret by 64 channels EEG signal

Regret is a negative social affect arising from upward counterfactual thinking for adverse outcomes. The neurophysiologic markers of identifying regret based on feature extraction from EEG signal has yet to be investigated. The EEG signals were recorded while 25 subjects performed a gambling task involving feedback for the subjects' chosen selection, the alternative selection, or for both. After the preprocessing, we extracted the ApEn (Approximate entropy) as the definitive feature. Regret as the target emotion was identified by the binary-class Fisher classifier, in comparison with each of the other three nontarget affect categories (i.e., disappointment, happiness and rejoice), which are also associated with the gambling task. The results show that regret is successfully identified from the other three nontarget affects. Notably, the significant difference is mainly distributed in anteromedian region, consistent with scalp distributions of EEGs evoked by regretful affect.